A New Frontier in Vascularized Engineered Tissue
Engineered human tissue has long promised to bridge the gap between cell cultures and human physiology, serving as a vital intermediary step before clinical trials. A key challenge has been supplying these three-dimensional constructs with a reliable blood supply. Without functional vascular networks, growing tissues face necrosis in their interiors and limited size, constraining their usefulness for research and potential therapies.
Researchers at Binghamton University, led by Ying Wang and Yingge Zhou from the Thomas J. Watson College of Engineering and Applied Science, report a breakthrough in how to create artificial vasculature using nanomanufacturing. Published in Biomedical Materials, their work demonstrates that ultra-fine, engineered microtubes can be integrated into a tissue scaffold to enhance perfusion and nutrient delivery, providing a more physiologically relevant environment for cells to thrive.
The Technique: From Solid Cores to Hollow Microtubes
The team constructed microtubes from two inert biomaterials commonly used in biomedical devices: polyethylene oxide (PEO) and polystyrene (PS). They relied on electrospinning, a technique that uses a powerful electric field to produce ultra-fine fibers, to fabricate the microtubes at the micron scale. A clever sequence then converts these solid microtubes into hollow channels: the core material is dissolved, and ultrasonic vibration helps regulate tube length so they disperse evenly rather than clump together.
“The microtubes are typically 1 to 10 microns in diameter,” Zhou explained. This scale is finer than most 3D printers can reliably achieve, making electrospinning essential for creating the hollow conduits needed for microvascular networks. Shorter, well-dispersed tubes are critical so they can be distributed throughout the hydrogel without compromising the scaffold’s structural integrity.
Integrating Microtubes with a Hydrogel Scaffold
Once prepared, the hollow microtubes are embedded within a composite hydrogel that forms the tissue-growing medium. The hydrogel simulates the extracellular matrix, providing a supportive environment for cells while offering pathways for fluid flow. To assess perfusion, the team used fluorescent microbeads as tracers, enabling them to visualize and quantify how well nutrients and oxygen could travel through the engineered tissue.
The results were clear: the microtubular network improved blood distribution within the scaffold, facilitating more uniform delivery of essential resources to cells. This enhanced perfusion helps maintain cell viability in the tissue’s interior, expanding the feasible size and complexity of engineered constructs.
Looking Ahead: Toward Organ-Specific and Multi-Organ Systems
Wang and Zhou see multiple avenues for refinement. They aim to explore how the dimensions and shapes of the microtubes influence vascular outcomes, with an eye toward tuning the channels for different tissue types. A particularly promising direction is the development of organ-specific microvasculature, such as the blood-brain barrier, which poses unique demands for selective permeability and tight junction integrity.
“We want to bring the physiological relevance of these engineered tissues closer to our own bodies,” Wang says. The long-term vision extends beyond a single organ: with further optimization, the researchers hope to assemble multi-organ systems composed of human cells that operate as a living, interconnected network, advancing both drug testing and potentially regenerative therapies.
Implications for the Field and Patient-Centric Outcomes
The study represents a meaningful step toward overcoming one of tissue engineering’s most stubborn hurdles: sustaining viable, vascularized tissue in three dimensions. By using nanomanufacturing to fabricate tunable microvasculature, researchers can create more faithful models of human biology. This not only accelerates preclinical testing but also improves the fidelity of disease models and the assessment of treatments that rely on intact microcirculation.
Author and Collaboration Notes
The work features contributions from doctoral students Xianyang Li, Sadia Khan, and Yan Chen; alumnus Liyuan Wang ’23; and postdoctoral researcher Xiang Fang, highlighting a collaborative effort across engineering disciplines within the university.
